The invention relates to an anti-slip device for the transport or the storage of parcels packed in or on wood or consisting of wood, such as for example wood packing cases or lumber or the like, which are tied with at least one strap.
Both in the case of transport within an industrial plant and in the case of transport outside of industrial plants, on trucks, cars, ships or the like, it is necessary to secure parcels reliably against slipping.
Protection against slippage to increase stackability is generally necessary whenever parcels have to be stacked one on the other in several layers. Unless such protection is provided, the stacks cannot be made very high. This is disadvantageous wherever it is generally desirable to stack goods to the greatest possible height for the optimum utilization of available floor space.
As an anti-slip device for goods packed in wood, such as wood cases or the like, or for goods packed on wood such as pallets, coil frames or the like, and for the prevention of the slippage of parcels consisting of wood such as lumber, logs or the like, a circular safety disk has been proposed which is provided with tooth-like projections around its margin, these fastening teeth projecting vertically upward from the upper side and vertically downward from the bottom side.
It has been found, however, that an anti-slip device of this kind does not satisfy requirements when the material to be secured against slippage is tied together with straps consisting generally of steel, i.e., flat bands of metal or plastic made endless in some suitable manner. However, this is frequently the case with parcels stacked on wood pallets and held in place thereon by strapping. Packing cases or the like are also frequency provided with metal strapping which is wrapped tightly about the parcels for the purpose of providing them with greater security in transport.
One important disadvantage of the above-mentioned, previously known anti-slip device consists in the fact that it cannot be properly placed in the area of the strap, since the fastening teeth are bent over when the parcel of material is lowered onto another parcel or onto a surface consisting of wood strapped with metal bands. If the strapping consists of plastic, it can be damaged by the teeth. The bending of the teeth in the area of the strapping will result in failure to achieve the desired intimate fastening between the wood pieces to be held together, since the teeth which are not in the area of the strapping will be unable, on account of the bent teeth, to penetrate as far into the wood as is desirable for secure fastening.
At the same time it must be considered that the strapping, precisely in the case of wooden packing cases or the like, is located in the area of the bearing surfaces, so that the anti-slip devices have to be placed there, not at other, more elevated locations.
Another disadvantage is that, when a truck, for example, is being loaded with a heavy packing case, it is extremely dangerous to insert the known disks by hand between the case and the platform or floor of the truck, since in this case the hands of the personnel come between the case and the floor or another case, so that when the material is lowered by a fork lift truck, a crane or the like, relatively severe injuries can be incurred.
An anti-slip device has become known which, in addition to the fastening teeth bent out approximately centrally from the top and bottom of a narrow metal strip, has a prolonged end which is not provided with fastening teeth, so that this known fastening means can be inserted from without between two parcels or between a parcel and a loading surface, without the above-mentioned danger of injury. With this known anti-slip device, however, a plurality of such parcels cannot be disposed closely adjacent one another as is desired as a general rule, since the free ends serving as handles project laterally. This lateral protrusion, however, not only prevents stacking parcels close together but also constitutes a considerable hazard, since this known anti-slip device must necessarily be made of metal. The hazard, however, threatens not only the personnel, but often the adjacent goods as well, when delicate material is involved, such as cardboard boxes or the like which are stacked on a pallet.